package reggie.fillter;

import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;
import reggie.common.BaseContext;
import reggie.common.R;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


@WebFilter(filterName = "LoginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1.获取本次请求的URI
        String requestURI = request.getRequestURI(); //backend/index.html

        log.info("拦截到请求：{}",requestURI);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
            "/employee/login",
            "/employee/logout",
            "/backend/**",
            "/front/**",
            "/common/**",
            "/user/sendMsg",
            "/user/login"
        };

        //2.判断本次请求是否需要处理
        boolean check = check(urls,requestURI);

        //3.如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4-1.判断登录状态，如果已经登录，则直接放行
        if (request.getSession().getAttribute("employee")!=null) {
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");

            //将用户id存入线程中去
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //4-2.判断登录状态，如果已经登录，则直接放行
        if (request.getSession().getAttribute("user")!=null) {
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");

            //将用户id存入线程中去
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        log.info("用户未登录!");

        //5.如果未登录则返回未登录结果，通过输入流方式向客户端页面响应数据

        response.setContentType("text/html;charset=utf-8");

        response.getWriter().write(JSON.toJSONString(R.error("未登录")));

        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    private boolean check(String[] urls, String requestURI) {
        for (String url: urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
